The Work Done by Gas Calculator computes the work performed during the expansion or compression of a gas using W=PΔVW = P \Delta VW=PΔV, where ΔV=Vf−Vi\Delta V = V_f – V_iΔV=Vf​−Vi​. By entering any three of the four variables (pressure, initial volume, final volume, work), the calculator determines the unknown. This tool is useful for thermodynamics students, chemistry labs, and engineering calculations to evaluate energy transfer in gas processes.